Looch,
I've found that measuring from the muzzle end as you have described above is the most fool proof way to determine certainly the location of a particular bullet as it engages the lands. I use a 1/4" wood dowel and masking tape to mark. I wouldn't tap the bullet but just drop it downward into the chamber and it will sort of stick there enough to use a rod from the muzzle end - or just push it in with a pencil. Then make up a dummy round at your COAL - WITHOUT POWDER OR PRIMER - and chamber it. Then test your COAL again with a rod from the muzzle end to the seated bullet tip. Another mark at the muzzle end will graphically display your "jump" to the lands.
Note that if your bullet is against the lands that condition may generate higher than wished for pressures. Usually seating just back from the lands (.020" or a slight bit more) is recommended for safety -especially with jacketed bullets. As has been mentioned I think, often your magazine or other feeding issues may prevent you from seating a particular bullet out to almost the lands. That's no biggy usually. Just roll with it and see how the shorter COAL shoots.
I've found that measuring from the muzzle end as you have described above is the most fool proof way to determine certainly the location of a particular bullet as it engages the lands. I use a 1/4" wood dowel and masking tape to mark. I wouldn't tap the bullet but just drop it downward into the chamber and it will sort of stick there enough to use a rod from the muzzle end - or just push it in with a pencil. Then make up a dummy round at your COAL - WITHOUT POWDER OR PRIMER - and chamber it. Then test your COAL again with a rod from the muzzle end to the seated bullet tip. Another mark at the muzzle end will graphically display your "jump" to the lands.
Note that if your bullet is against the lands that condition may generate higher than wished for pressures. Usually seating just back from the lands (.020" or a slight bit more) is recommended for safety -especially with jacketed bullets. As has been mentioned I think, often your magazine or other feeding issues may prevent you from seating a particular bullet out to almost the lands. That's no biggy usually. Just roll with it and see how the shorter COAL shoots.
